int indexOf(String str)Returns the index within this string of the first occurrence of the specified substring.

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int indexOf(String str, int fromIndex) Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.

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int lastIndexOf(String str)Returns the index within this string of the rightmost occurrence of the specified substring.

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int lastIndexOf(String str, int fromIndex)Returns the index within this string of the last occurrence of the specified substring.

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int length()Returns the length (character count) of this string buffer.

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void setCharAt(int index, char ch)The character at the specified index of this string buffer is set to ch.

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void setLength(int newLength)Sets the length of this String buffer.

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CharSequence subSequence(int start, int end) Returns a new character sequence that is a subsequence of this sequence.

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String substring(int start)Returns a new String that contains a subsequence of characters currently contained in this StringBuffer.The substring begins at the specified index and extends to the end of the StringBuffer.

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String substring(int start, int end)Returns a new String that contains a subsequence of characters currently contained in this StringBuffer.

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String toString() Converts to a string representing the data in this string buffer.